Automatic ISDN switch

ABSTRACT

An automatic ISDN switch for connection to at least one ISDN-BRI line and a plurality of different videoconferencing locations for automatically switching the at least one ISDN-BRI line to one videoconferencing location of the plurality of different videoconferencing locations, comprising: a control unit for being placed in circuit communication with each of the plurality of different videoconferencing locations, the control unit generating a location signal corresponding to a particular one videoconferencing location of the plurality of videoconferencing locations; and a switch bank in circuit communication with the control unit for receiving the location signal, for being placed in circuit communication with the plurality of different videoconferencing locations, and further for being placed in circuit communication with the at least one ISDN-BRI line, said switch bank automatically switching the at least one ISDN-BRI line to the particular one videoconferencing location of the plurality of videoconferencing locations corresponding to the location signal generated by the control unit. In one embodiment of the present invention, an automatic ISDN switch automatically determines the location of the target videoconferencing location and switches the incoming ISDN-BRI lines to the target location without requiring any manual routing of ISDN-BRI lines. In another embodiment of the present invention, an automatic ISDN switch is in circuit communication with an external communication device via a communications link, with which a user causes the switch to automatically switch the incoming ISDN-BRI lines to the target location without requiring any manual routing of ISDN-BRI lines. Both embodiments eliminate the need for manual patch panels and dedicated, costly ISDN-BRI lines to all locations.

FIELD OF THE INVENTION

[0001] The present invention relates generally to switching ofcommunication signals, e.g., integrated services digital network(“ISDN”) signals. A preferred embodiment of the present invention is anautomatic ISDN switch that automatically detects the presence of an ISDNdevice at one of a plurality of locations and automatically routes allaudio, video, and data to that one location while locking out all of theother locations connected to the switch. The ISDN switch of the presentinvention has numerous applications, including by way of examplevideoconferencing using a 128 kbps (128,000 bits per second), 256 kbps,384 kbps, or 512 kbps ISDN configuration.

BACKGROUND OF THE INVENTION

[0002] Videoconferencing has recently undergone an evolution. Prior tothis evolution, videoconferencing equipment was typicallysemi-permanently installed in a dedicated location with dedicated,permanently installed communication lines. The recent evolution took theform of making videoconferencing equipment mobile. In the past fewyears, most videoconferencing equipment on the market has been marketedas being mobile and by far the majority of videoconferencing systemssold over the past few years have been mobile systems.

[0003] There are a number of standard communications methodologies thatcan be used in videoconferencing. Currently, the most widely usedvideoconferencing communications medium in the United States andinternationally is ISDN, which is the basis for a number of differentspecific communications configurations. One ISDN videoconferencingcommunications family of standards is known as H.320 (ITU-T) promulgatedby the International Telecommunications Union (formerly known as CCITT).One implementation allows 384 kbps transmission of information usingthree individual ISDN-BRI (Integrated Services Digital Network-BasicRate Interface) telephone lines. This form of videoconferencetransmission is also known or described as “six-channel transmission” inthe videoconference industry, because it uses six ISDN channels, each ofwhich carry 64 kbps of digital information. Each ISDN-BRI telephone lineincludes two separate 64 kbps lines or channels, as they are referred toin the videoconferencing industry. The H.320 standard encompasses video(e.g., videoconferencing), audio, and control using one or more 64 kbpsISDN lines. A majority of corporate videoconferencing installationscurrently use six 64 kbps ISDN lines, using three two-channel ISDN-BRIlines; while other applications such as medical videoconferencingapplications use as many as eight 64 kbps ISDN lines.

[0004] One obvious benefit of using mobile ISDN videoconferencingequipment is that one videoconferencing unit can be used at a number oflocations in the same facility. However, connecting ISDN devices to anISDN line is complicated by the fact that ISDN lines must be properlyterminated with an industry standard network U-interface, such as anNT-1, an NT-3, or a Triple NT-1. Only a single device (more specificallya U-interface) may be connected to a BRI line. Businesses requiring useof ISDN lines in more than one location have had two acceptable priorart options: (i) installing multiple data lines for each possiblelocation or (ii) installing a patch panel at the point of terminationwith which one can physically manipulate the termination point of theISDN line(s). A third prior art option, daisy-chaining, is not anacceptable option because it has problems of signal quality consistency,security, and accessibility, as will be discussed below.

[0005] The first prior art option, installing multiple data lines foreach possible location, is very costly and inconvenient. Oneimplementing the first prior art option would be charged for theinstallation of each set of three ISDN lines (recall that with themajority of corporate or industrial videoconferencing installations-ascompared to typical home usage-each location requires access to threetwo-channel BRI telephone lines), the digital monthly services chargesfor each set of three ISDN lines for each location, even when lines arenot used, and the cost of the (3) CAT-5 wires to each location beyondthe initial point of termination. Thus, to implement this first optionusing current wiring standards, it is necessary to run multiple datalines from the point of presence (the phone room in typicalinstallations) to each possible destination. If, for example, a 384 kbpsISDN configuration were to be needed in 3 different rooms, it would benecessary for a total of 9 data lines be run (3 ISDN 2 channel linesfrom point of presence to destination). The cost and type of cablingmust be considered for such an implementation; expensive CAT-5 or CAT-6wiring is specified. The cost of this option can become prohibitive withonly a few locations. Moreover, under these stringent installationmethods, flexibility of conference locations is not an option due to thefact that the wiring must be permanently installed.

[0006] Additionally, the first prior art option is inconvenient to usewith a mobile videoconferencing unit. As known to those in the art, eachvideoconferencing system has an ISDN network interface (e.g., an NT-1,an NT-3 or an Triple NT-1) that acts to terminate the ISDN line(s) usedin that system and an ISDN video codec. Each 64 kbps ISDN line has itsown unique telephone number. As also known to those in the art, the ISDNvideo codec must be programmed with the telephone number(s) for eachISDN line(s) used. Thus, moving a mobile videoconferencing unit from onelocation to another requires that six telephone numbers be programmedinto the ISDN video codec, which typically must be done by busy MISpersonnel. At least one ISDN video codec in the art, i.e., a unit fromPolycom Inc., includes software that attempts to automatically detectthe phone numbers associated with the ISDN lines and program thosenumbers into the video codec. However, this autodetection process cantake 5-10 minutes and is not always successful; the system might fail todetect the telephone numbers. Also, executing the autodetection processstill typically requires MIS personnel to perform.

[0007] The second prior art option is to install a patch panel in thetelephone closet or another location with which one can physicallymanipulate the termination point of the ISDN line(s). This option has agreat deal more flexibility than the first option, in that one can wiremultiple rooms for access and simply ‘patch’ the data lines to thedestination at the time of need; however, it suffers from relativelyhigh cost and is inconvenient as well.

[0008] More specifically, the second option requires that allcommunication lines be brought to the point of presence and terminatedin a patch bay. Located near the incoming patch bay, typicallyunderneath, is a patch panel. Simply put, the electrical connectionbetween the patch bay and the patch panel resembles the old switchboardbanks that telephone operators would use to directly electricallyconnect a caller to a destination. The same antiquated manual processused to route telephone calls before and during the 1950's is currentlyused to route ISDN lines with the patch panel. Because ISDN technologyrequires termination at each end to properly operate, the patch panelroutes the ISDN lines to a single termination point and isolates allother signal access locations. The patch panel has the benefit of givingthe user security, in that the data lines can only be connected to asingle destination; therefore, eavesdropping through another room is notpossible. Another advantage of the patch bay over the first prior artoption is that there is flexibility in provisioning data lines; moredata lines can be added without changing the wiring plant. In thealternative, manual switches are used instead of the manual patch panelin this prior art option.

[0009] There are difficulties with the patch panel method of connectingISDN lines as well. One of the primary drawbacks of using a patch panelto route ISDN lines to various destination locations is inconvenience.Switching the ISDN lines from one location to another requires that atechnically capable person be notified and available, in advance, whenand where an ISDN line is needed so that the appropriate cables can bemanually connected or switched ahead of time. Another primary concern iscost of implementation. It is still necessary for a videoconferencingapplication implemented with this second option, using currentvideoconferencing wiring conventions, to run multiple data lines to eachpossible location. Yet another concern is that an error in patching canprevent the system from functioning at all.

[0010] One common method of connecting multiple devices to a singleline, daisy-chaining, is not a realistic option for ISDN lines, becauseof termination issues. This issue can be understood in contrast to theplain old telephone system (POTS).

[0011] In a normal home telephone environment, using POTS telephonelines, it is common practice to attach multiple telephones to a singleline by connecting them one to another in a daisy chain format.Daisy-chaining devices causes several potential problems, such as anobvious decrease in sound volume. This is acceptable when using ordinarytelephones connected to POTS telephone lines because human ears are muchmore flexible and less demanding than computer equipment, i.e., our earscan still understand what is being said despite changes in signalquality and volume caused by daisy-chaining. The termination point canbe at any telephone connected to the POTS telephone line, and can changefrom usage to usage as different handsets are used. Thus, with ordinarytelephones connected to POTS telephone lines, the termination (or endpoint of the wire) does not have to be defined in advance as long ascertain minimum requirements are made (e.g., limiting the total numberof devices daisy chained together). In addition to changes in signalquality and volume, daisy-chaining causes other problems. For example,when a conversation is taking place on the telephone, it is possible toeavesdrop by picking up another extension. Another concern is that aphysically damaged wire or jack can prevent all telephone sets afterthat point from functioning.

[0012] These problems with daisy-chaining are a great deal morepronounced with a digital protocol, such as ISDN. The signal sensitivityin a digital line must be constantly maintained in order for accurateand consistent data transmissions to take place. If, during avideoconferencing session at one location, another videoconferencingunit is connected to the same ISDN line, the signal loss caused by thatother connection being made (made possible only because of the inadviseduse of daisy-chaining) may cause one or more channels to be lost, or theentire call to be disconnected. Also, ISDN lines must have a fixed,predetermined termination point. Unlike the procedure for ordering astandard home telephone line, when provisioning (or ordering) a digitalISDN line one is required to specify a single termination point for thatISDN line for the installation to occur.

SUMMARY OF THE INVENTION

[0013] According to the present invention, an automatic ISDN switch isprovided that avoids the need for patch panels, costly dedicated ISDNlines to all locations, and use of MIS personnel to switching patchpanel wires. The present invention also includes a novel wiringconfiguration that significantly reduces the cost of wiring ISDNinstallations.

[0014] According to one aspect of the present invention, an automaticISDN switch automatically determines the location of the targetvideoconferencing location and switches the incoming ISDN lines to thetarget location without requiring any manual routing of ISDN lines. TheISDN switch of the present invention comprises a switch bank in circuitcommunication with a control unit. In short, the control unit determinesto which location the ISDN line(s) from the telephone company should beswitched, and the switch bank switches the ISDN line(s) from thetelephone company to a particular location. In a first embodiment, thecontrol unit comprises autodetect logic that automatically detects thelocation of videoconferencing equipment and transmits a signal to theswitch bank indicating to which location signal the ISDN line(s) fromthe telephone company should be switched. The autodetect logic can useany number of ways of detecting the location to which the ISDN line(s)from the telephone company should be switched, including by way ofexample, but not of limitation, detecting that a connector has beeninserted into a receptacle, detecting that two conductors have beenelectrically shorted, detecting that the impedance between twoconductors has changed, detecting that the electrical characteristics ofat least one conductor have changed, detecting that videoconferencingequipment at a particular location has been powered up, a particulartelephone extension being dialed from the particular location, etc. Thecontrol unit can be connected to the various locations by any suitableconnection, e.g., by way of example but not of limitation, via one ormore of the following circuit communications means: one or moreconductor(s), connector(s), computer network(s), fiber optic link(s),optical signals(s), radio signal(s), electromagnetic signal(s),telephone line(s), sonic link(s), ISDN lines, hybrid ISDN lines,existing Ethernet cable(s), power line(s) (using, e.g., an X-10interface), etc.

[0015] In a second embodiment of the present invention, the control unitcomprises a communication circuit supporting a communications link to acommunications device to allow a user to directly select the location towhich the ISDN line(s) from the telephone company should be switched,including by way of example, but not of limitation: a keypad located inone or more locations to which ISDN line(s) from the telephone companycould be switched (e.g., videoconferencing locations), a pass key readerin one or more of the locations, a keypad located on the enclosure forthe control unit and/or the switch bank, a keypad at a locationdifferent from where the control unit and/or switch bank are located anddifferent from the one or more locations, a telephone extension throughwhich a user might select the particular location, a computer terminalthrough which a user might select the particular location, a web sitethrough which a user might select the particular location, anelectromagnetic link through which a palmtop computer might be used toselect the desired location, etc. The control unit can be connected tothe communications device by any suitable connection, e.g., by way ofexample but not of limitation, via one or more of the following circuitcommunications means: one or more conductor(s), connector(s), computernetwork(s), fiber optic link(s), optical signal(s), radio signal(s),electromagnetic signal(s), telephone line(s), sonic link(s), ISDN lines,hybrid ISDN lines, existing Ethernet cable(s), power line(s) (using,e.g., an X-10 interface), etc.

[0016] Any combination of one or more of the implementations of thefirst embodiment can be combined with any combination of one or more ofthe implementations of the second embodiment to provide enhancedfunctionality.

[0017] According to the novel wiring configuration of the presentinvention, two or more ISDN lines are used with a single cable. In oneembodiment, a plurality of ISDN-BRI lines are combined on a singlehybrid line to provide enhanced throughput. These lines are “hybrid” inthe sense that they ignore industry standard wiring conventions (AT&TBell Laboratories Std. No. 568-B for videoconferencing) for CAT-5 andCAT-6 wiring used in an ISDN videoconferencing application; i.e., morethan one ISDN-BRI line is passed through a single CAT-5 or CAT-6 singlecable. In the case of a 384 kbps videoconferencing system, the threeISDN-BRI lines (six 64 kbps lines) can be passed through six of theeight available conductors in a CAT-5 or CAT-6 cable (or a cablesuitable for Ethernet applications), leaving two lines for theautodetect logic and/or the communication circuit in the control unit.The novel wiring convention of the present invention arose out of anawareness that, using wiring conventions for videoconferencing, a majorimpediment to the marketing and installation of videoconferencingsystems is the cost and complexity associated with installing new wiringrequired with typical videoconferencing installations. This awareness,coupled with a knowledge that most conference rooms and offices arewired with a single unshielded twisted pair (“UTP”, which actually hasfour such twisted pairs) cable for Ethernet applications, and that thatEthernet cable is rarely used in conference rooms, and further coupledwith insight that UTP cables suitable for Ethernet applications wouldalso be suitable for a plurality 64 kbps ISDN lines in violation ofvideoconferencing wiring conventions, led to the concept of using thehybrid ISDN lines of the present invention. Thus, according to thepresent invention, existing UTP wiring found in most conference roomscould be used as-is for 384 kbps or 512 kbps videoconferencingapplications.

[0018] The novel wiring configuration of the present invention can beused for any number of applications requiring more than two 64 kbps ISDNlines. For example, in the case of a 512 kbps medical application, fourISDN-BRI lines (eight 64 kbps lines) can be passed through the eightavailable conductors in a CAT-5 or CAT-6 cable (or cable for Ethernetapplications), and the autodetect logic and/or the communication circuitin the control unit must use another communication path (e.g., telephonelines, RF signal, etc.) to either autodetect or receive a communicationabout the desired location, unless some of the eight availableconductors in the CAT-5 or Ethernet cable are used for both detectionand the ISDN signals.

[0019] It is therefore an advantage of the present invention to providean ISDN switch that does not require human intervention in the form ofmanually switching one or more ISDN lines to a particular location.

[0020] It is therefore another advantage of the present invention toprovide an ISDN switch that automatically detects a location requiringthe use of one or more ISDN lines.

[0021] It is a further advantage of this invention to provide an ISDNswitch that automatically detects a location requiring the use of one ormore ISDN lines and that automatically switches the ISDN lines to thatlocation without requiring any manual routing, patching, or switching ofISDN lines.

[0022] It is yet another advantage of the present invention to allow asignificant cost savings by using hybrid ISDN lines in which more thanone ISDN signal is passed through a single ISDN cable.

[0023] It is still another advantage of the present invention to allow asignificant cost savings by using hybrid ISDN lines in which more thanone ISDN signal is passed through an existing cable for use in anEthernet application.

[0024] It is further still another advantage of the present invention toallow a significant cost savings by allowing all three ISDN-BRI lines ina 384 kbps videoconferencing application to be passed through a singleCAT-5 or CAT-6 cable.

[0025] These and other advantages of the present invention will becomemore apparent from a detailed description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In the accompanying drawings, which are incorporated in andconstitute a part of this specification, embodiments of the inventionare illustrated, which, together with a general description of theinvention given above, and the detailed description given below serve toexample the principles of this invention.

[0027]FIG. 1 is a schematic block diagram of a very basic,semi-permanently installed prior art 384 kbps videoconferencing system;

[0028]FIG. 2 is a schematic block diagram of a prior art multiplelocation system implementing a prior art option for using onevideoconferencing system at multiple locations-installing a patch panelat the point of termination with which one can physically manipulate thetermination point of the ISDN line(s);

[0029]FIG. 3 is a schematic block diagram of a multiple location systemimplementing the communications switch of the present invention;

[0030]FIG. 4 is a schematic block diagram of an embodiment of themultiple location system of FIG. 3 showing an ISDN switch and novelcabling of the present invention for use with a 384 kbpsvideoconferencing application (i.e., for 128 kbps, 256 kbps, or 384 kbpsvideoconferencing);

[0031]FIG. 5 is a schematic block diagram of a generic automatic switchof the present invention;

[0032]FIG. 6 is a schematic block diagram of an automatic switchaccording to the present invention with autodetection of the desiredlocation using a communications link routed along with switchedcommunications lines;

[0033]FIG. 7 is a schematic block diagram of the ISDN switch of FIG. 4;

[0034]FIG. 8a is an isometric view of the ISDN switch of FIGS. 4 and 7mounted in a 19″ rack;

[0035]FIG. 8b is a front view of the front panel of the ISDN switch ofFIGS. 4 and 7-8 a;

[0036]FIG. 8c is a schematic block diagram of a breakout cable for theISDN switch of FIGS. 4, 7, 8 a and 8 b;

[0037]FIG. 9 is a schematic block diagram of a portion of the switchbank of the ISDN switch of FIG. 4, 7, 8 a, 8 b, and 8 c;

[0038]FIG. 10 is a schematic block diagram of a portion of the controlunit of the ISDN switch of FIG. 4, 7, 8 a, 8 b, 8 c, and 9;

[0039]FIG. 11 is a schematic block diagram of an embodiment of anautomatic switch according to the present invention with a communicationcircuit for communication with the various locations via communicationlinks routed with switched communications lines and autodetection of thedesired location using those communication links;

[0040]FIG. 12 is a schematic block diagram of an embodiment of anautomatic switch according to the present invention with a communicationcircuit for communication with the various locations via communicationlinks routed other than with switched communications lines andautodetection of the desired location using those communication links;and

[0041]FIG. 13 is a schematic block diagram of an embodiment of anautomatic switch according to the present invention with a communicationcircuit for communication with at least one communication device via atleast one communication link.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0042] Before describing the details of the present invention, adescription of several generic prior art videoconferencing systems maybe helpful in understanding the advantages of the automatic ISDN switchof the present invention. Reference is had, therefore, to FIG. 1, whichshows the very basic, semi-permanently installed prior art 384 kbpsvideoconferencing system 10. The videoconferencing system 10 includes amonitor 12, at least one speaker 13, a camera 14, and a microphone 15 incircuit communication with a video encoder/decoder (“codec”) 16 viaconnections 18, 19, 20, and 21, respectively, as is known to thoseskilled in the art.

[0043] “Circuit communication” as used herein is used to indicate ancommunicative relationship between devices. Direct electrical andoptical connections and indirect electrical and optical connections areexamples of circuit communication. Two devices are in circuitcommunication if a signal from one is received by the other, regardlessof whether the signal is modified by some other device. For example, twodevices separated by one or more of the following-transformers,optoisolators, digital or analog buffers, analog integrators, otherelectronic circuitry, fiber optic transceivers, or even satellites-arein circuit communication if a signal from one reaches the other, eventhough the signal is modified by the intermediate device(s). As a finalexample, two devices not directly connected to each other, but bothcapable of interfacing with a third device, e.g., a CPU, are in circuitcommunication.

[0044] The codec 16 is in circuit communication with an ISDN networkinterface 24 via three ISDN lines 26 a-26 c. The codec 16 is avideoconference system codec and encodes all out-going audio, video, anddata signals and decodes all incoming audio, video, and data signals.The codec 16 encodes the electrical signals representing the visualimage captured by the camera 14 and the audio received by the microphone15. The codec 16 also simultaneously decodes encoded visual signals andencoded audio signals received via the network interface 24 to generatethe video signal on line 18 displayed by monitor 12 and the audio signalon line 19 played by speaker 13. The network interface 24 (e.g., NT-1,NT-3 or Triple NT-1) is in circuit communication with a patch bay 30 viathree ISDN lines 32 a-32 c and three ISDN lines 34 a-34 c. The ISDNlines 32 a-32 c are connected to ISDN lines 34 a-34 c via RJ-45wall-jack connectors 36 a-36 c passing through wall plates 38 a-38 c inwall 39. RJ-45 connectors 40 a-40 c connected to the end of lines 32a-32 c complete the circuit communication to the RJ-45 wall-jackconnectors 36 a-36 c.

[0045] The patch bay 30 is typically located in a telephone closet orcomputer control room and provides an interface for three ISDN-BRI lines48 a-48 c provided by the local carrier. The ISDN lines 32 a-32 c, 34a-34 c, and 48 a-48 c are all an ISDN U interface. The three ISDN lines26 a-26 c are an ISDN S/T interface. The network interface 24 convertsthe ISDN U interface into an ISDN S/T interface.

[0046] The prior art system 10 in FIG. 1 is a single location system.The ISDN lines 32 a-32 c, 34 a-34 c, and 48 a-48 c are the only lines towhich the system 10 can be connected. To implement the first option fora prior art multiple location system-installing multiple data lines foreach possible location-one merely duplicates particular components ofFIG. 1 (ISDN lines 34 a-34 c and 48 a-48 c; RJ-45 wall-jack connectors36 a-36 c; patch bay 30; and wall plates 38 a-38 c) for each location. Asingle, larger patch bay can be used to support multiple locations.

[0047] Referring now to FIG. 2, there is shown a prior art multiplelocation system implementing the second prior art option-installing apatch panel at the point of termination with which one can physicallymanipulate the termination point of the ISDN line(s). The system of FIG.2 is similar in many respects to the system in FIG. 1, except (i) thesingle line patching area 70 in FIG. 1 is replaced by a multiple linepatching area 72 of FIG. 2 and (ii) the videoconferencing equipment(monitor, speaker, camera, microphone, video codec, network interface,and associated connections; all not shown in FIG. 2) is mobile in thesystem in FIG. 2 rather than being semi-permanently installed as in FIG.1.

[0048] The multiple line patching area 72 of FIG. 2 has a patch bay 74that is identical to patch bay 30 in FIG. 1, and a patch panel 76, notfound in the system of FIG. 1. As in FIG. 1, three incoming ISDN-BRIlines 48 a-48 c provided by the local carrier are connected to the patchbay 74. These ISDN-BRI lines are in circuit communication between thepatch bay 74 and the patch panel 76 as three manually switchableISDN-BRI patch cables 78 a-78 c. The patching area 72 of FIG. 2 has sixgroups of three ISDN-BRI output lines 80A-80F. The three ISDN-BRI linesrouted to location A (80A) are shown as 34 a-34 c (as in FIG. 1) and thewiring between the patching area 72 and the wall plates (not shown inFIG. 2) are identical to that shown in FIG. 1 for each location. Themobile video conferencing equipment can be moved to as to be connectedat location A to lines 80A, at location B to lines 80B, at location C tolines 80C, at location D to lines 80D, at location E to lines 80E, or atlocation F to lines 80F. Thus, in the patch panel in FIG. 2, a total ofeighteen ISDN-BRI lines exit the patch panel 76. The patch panel 76 alsohas eighteen jacks: A1, A2, A3, B1, B2, B3, C1, C2, C3, D1, D2, D3, E1,E2, E3, F1, F2, and F3. Each of the eighteen jacks is connected to oneof the eighteen individual ISDN-BRI lines exiting patch panel 76. Forexample, jack A1 82 is directly electrically connected to line 34 a,jack A2 84 is directly electrically connected to line 34 b, and jack A386 is directly electrically connected to line 34 a.

[0049] In the prior art system shown in FIG. 2, location A is the activelocation and lines 34 a-34 c are in circuit communication with the threeISDN-BRI lines 48 a-48 c, respectively. The fifteen lines 80B-80F tolocations B-F are left open, i.e., not in circuit communication. To makeanother location the active location, e.g., location C, one must removeISDN-BRI patch cables 78 a-78 c from jacks A1 82, A2 84, and A3 86 inthe patch panel and reinsert them into jacks C1 88, C2 90, and C3 92.

[0050] Referring now to FIG. 3, a multiple location system 90 accordingto the present invention is shown. The system 90 is in circuitcommunication with a device 91 requiring access to at least onecommunications line. More specifically, in the videoconferencingcontext, the system 90 includes the same videoconferencing equipment 91(monitor 12, speaker 13, camera 14, microphone 15, video codec 16,network interface 24, and associated connections 18-21, and 26 a-26 c)as FIG. 1, except the videoconferencing equipment 91 is mobile, like inthe system in FIG. 2. The system 90 in FIG. 3 includes an automaticcommunications switch 92 according to the present invention. Theautomatic switch 92 is in circuit communication with at least oneunswitched communication line 93, which is/are switched by the automaticswitch 92 to a plurality of switched communication lines 94-1, 94-2, . .. 94-n, with each of the switched communication lines 94-1, 94-2, . . .94-n being in circuit communication with one of a plurality of differentlocations 1-n. The videoconferencing equipment 91 is in circuitcommunication with one of the locations 1-n, specifically location n inFIG. 3. The automatic switch 92 includes a control unit and a switchbank (neither shown in FIG. 3). As further explained herein, the controlunit determines to which particular location of the plurality locations1-n the at least one communication line 93 is to be connected and theswitch bank switches at least one of the at least one communication line93 to that location. In the broadest sense, the control unit candetermine one of a plurality of locations requiring access to acommunications line and the switch bank can switch an appropriate numberof communication lines to each such location.

[0051] Referring now to FIG. 4, a multiple location system 100 accordingto the present invention is shown. The system 100 is a 384 kbpsvideoconferencing system and includes the same videoconferencingequipment 102 (monitor 12, speaker 13, camera 14, microphone 15, videocodec 16, network interface 24, and associated connections 18-21, and 26a-26 c) as FIG. 1, except the videoconferencing equipment 102 is mobile,like in the system in FIGS. 2 and 3. The system 100 in FIG. 4 includesan automatic ISDN switch 104 according to the present invention. Theautomatic ISDN switch 104 is in circuit communication with at least onecommunication line, which is/are switched by the automatic ISDN switch104, with switched communication lines being in circuit communicationwith a plurality of different locations (with or without the use ofhybrid lines).

[0052] In the system of FIG. 4, the communication lines are ISDN Uinterfaces from the central office or local carrier, specifically threesuch ISDN U interfaces 48 a-48 c. These lines will be referred to hereinas “inputs” or “input lines.” The plurality of different locations arerepresented by locations A-F in FIG. 4. In FIG. 4, the switchedcommunication lines are switched ISDN U interfaces 105A-105F, which areconnected to the automatic ISDN switch 104 via signal outputs 106A-106F.

[0053] The terms “input” and “output” and “input line” and “output line”and “output location” are used very loosely herein with respect to ISDNlines. ISDN U interfaces by their very nature are bidirectional;therefore, strictly speaking, ISDN U interfaces are both input lines andoutput lines. However, to offer a distinction between (i) the unswitchedISDN U interfaces 48 a-48 c from the central office or local carrier(not shown) and (ii) switched ISDN U interfaces 105A-105F, the followingwill be used: (a) the unswitched ISDN U interfaces 48 a-48 c will bereferred to as “inputs” and “input lines,” which are connected to switch104 via “signal inputs” 108 a-108 c, and (b) switched ISDN U interfaces105A-105F will be referred to as “outputs” and “output lines,” which areconnected to switch 104 via “signal outputs” 106A-106F.

[0054] Each switched communication line is in circuit communication witha single location of the plurality of locations via any suitable circuitcommunication means, including by way of example but not of limitation,one or more conductor(s), connector(s), computer network(s), fiber opticlink(s), optical signal(s), radio signal(s), electromagnetic signal(s),telephone line(s), sonic link(s), ISDN lines, hybrid ISDN lines,existing Ethernet cable(s), power line(s) (using, e.g., an X-10interface), etc. In FIG. 4, the switched communication lines 105A-105Fare preferably eight-conductor CAT-5 or CAT-6 cables acting as hybridISDN lines. More specifically, in the embodiment of FIG. 4, eachswitched communication line 105 has three ISDN-BRI lines (six 64 kbpslines) on three of the four twisted pairs therein, leaving one moretwisted pair in the cable for either autodetection by or communicationwith the control unit (not shown) in the switch 104.

[0055] The switched communication lines 105A-105F are routed from theswitch 104 to the locations A-F and connect to those locations at RJ-45wall-jack connectors 110A-110F passing through wall plates 112A-112F inwalls 114A-114F. One connects the network interface 24 of thevideoconferencing equipment 102 to one of the switched ISDN lines105A-105F via a custom breakout cable 113. The custom breakout cable 113divides a hybrid ISDN line portion 114 into three ISDN-BRI lines 116a-116 c and has a single RJ-45 connector 119 at one end and three RJ-45connectors 118 a-118 c at the other end.

[0056]FIG. 5 shows a generic automatic switch 92 according to thepresent invention. The switch 92 is in circuit communication with the atleast one unswitched communication line 93 from the central office orlocal carrier and the plurality of locations via a plurality of switchedcommunication lines 94-1, 94-2, . . . 94-n. The unswitched communicationline 93 is passed into the switch 92 as unswitched communication line154. The plurality of switched communication lines 94-1, 94-2, . . .94-n are passed from the switch 92 as a plurality of switchedcommunication lines 155-1, 155-2, . . . 155-n. The switch 92 comprises aswitch bank 150 in circuit communication with a control unit 152 via alocation signal 156. The switch bank 150 is also in circuitcommunication with the at least one unswitched communication line 154and the plurality of switched communication lines 155-1, 155-2, . . .155-n. The control unit 152 generates a location signal 156 (i.e.,alters the characteristics of the signal(s), if any, of the locationsignal 156 present prior to the generation by the control unit)corresponding to a particular one location of the plurality oflocations. In response, the switch bank 150 automatically switches theat least one unswitched communication line 154 to a particular one ofthe plurality of switched communication lines 155-1, 155-2, . . . 155-ncorresponding to the particular one of the plurality of locationsindicated by the location signal 156.

[0057] In general, the control unit 152 performs at least two basicfunctions: determining (or allowing a user to communicate) whichparticular location requires the use of the at least one communicationline and communicating that particular location to the switch bank 150.In the alternative, the control unit 152 can perform additionalfunctions, such as (i) determining (or allowing a user to communicate)whether permission has been granted for the at least one communicationline to be used at that particular location at that particular timeand/or (ii) determining (or allowing a user to communicate) which of aplurality of unswitched communication lines should be allocated to oneor more locations and/or (iii) implementing a communication link and/orproviding status information.

[0058]FIG. 6 shows an embodiment of switch 92 having a control unit 152that comprises autodetect logic 160, which determines to which oflocations 1-n the at least one unswitched communication line 154 shouldbe switched based on one or more activities being performed in theparticular location. Autodetect logic 160 is in circuit communicationwith each of the plurality of locations 1-n. Autodetect logic 160 can beimplemented in hardware, in executable code, in a combination ofhardware and executable code, and by other means. In FIG. 6 autodetectlogic 160 is in circuit communication with each of the plurality oflocations 1-n via lines 162-1, 162-2, . . . 162-n, which pass to thelocations 1-n with switched communication lines 155-1, 155-2, . . .155-n via lines 94-1, 94-2, . . . 94-n. Each of lines 162-1, 162-2, . .. 162-n comprise at least one communication path with which autodetectlogic 160 determines to which of locations 1-n the at least oneunswitched communication line 154 should be switched. When the at leastone communication path of lines 162-1, 162-2, . . . 162-n comprise atleast one conductor, autodetect logic 160 can make this determinationby, by way of example but not of limitation: detecting a change in theelectrical state of the at least one conductor connecting to theparticular location, detecting that first and second conductorsconnecting to the particular location have been shorted together,detecting a change in the electrical relationship between first andsecond conductors connecting to the particular location, detecting achange in the impedance between first and second conductors connectingto the particular location.

[0059] For the autodetect logic in the embodiment of FIG. 6, it mattersnot what causes the change in the communication path 162. The change inthe communication path (e.g., change in the electrical state of the atleast one conductor, first and second conductors connecting to theparticular location being shorted together, change in the electricalrelationship between first and second conductors, change in theimpedance between first and second conductors, etc.) can be caused bynumerous ways, all of which are contemplated to be within the scope ofthe present invention. These changes can be caused by, by way of examplebut not of limitation: (a) electrical conductors within a connectorplugged into a receptacle in circuit communication with the autodetectlogic 160, (b) a push-button located at the particular location (e.g.,located on the wall plate used to connect to the switched communicationline(s), located on the wall above the wall plate used to connect to theswitched communication line(s), located on a cable used to connect tothe switched communication line(s), located on the videoconferencingequipment, etc.) and causing the change in the communication path inresponse to the switch being pressed or actuated, (c) a circuitincluding a keypad, capable of making a determination on its own whetherany keys pressed are valid and causing the change in the communicationpath in response to a proper sequence of keys being actuated, andlocated at the particular location (e.g., located in any of thelocations listed above), (d) a circuit including a key card reader,capable of making a determination on its own whether a key card is validand causing the change in response thereto, and located at theparticular location (e.g., located in any of the locations listedabove), (e) a circuit including a sensor (e.g., voice sensor, retinalscanner, thumb print scanner, hand print scanner, another scanner,etc.), capable of making a validation determination on its own andcausing the change in response thereto, and located at the particularlocation (e.g., located in any of the locations listed above).

[0060] As shown in FIG. 6 and as discussed above, the communication path162 is separate from the switched communication lines 155. In thealternative, the switched communication lines 155 can be used for bothautodetection and communication, without the need for separateadditional lines being run from the switch 92 to the locations. This canbe important for applications requiring all eight conductors in a CAT-5cable, such as 512 kbps medical videoconferencing applications; thereare no spare conductors left over to form a communication link to theautodetect logic 160. In this alternative embodiment, the switchedcommunication lines 155 would be used first as a communication path 162to communicate with the autodetect logic 160 and then as switchedcommunication lines 155, since the switched communication lines wouldnot need to carry information from the unswitched communication lines154 until after a determination of the particular location has beenmade. The remainder of this alternative embodiment would be the same asthe FIG. 6 embodiment.

[0061]FIG. 6 and the accompanying text describe embodiments of thepresent invention somewhat generally. FIGS. 7-10 show schematically aembodiment of a switch 104 specifically for a 384 kbps ISDNvideoconferencing system with autodetection of the particular locationbased on inserting the ISDN connector from the videoconferencingequipment into the ISDN receptacle at that location.

[0062]FIG. 7 is a schematic block diagram of the switch 104 specificallyfor a 384 kbps videoconferencing application. The switch 104 of FIG. 7is for use in the system of FIG. 4 and described in the accompanyingtext, and has three unswitched ISDN-BRI U interfaces 48 a-48 c switchedto six possible locations A-F via switched ISDN U interfaces 105A-105F.Switch 104 comprises a switch bank 180 in circuit communication with acontrol unit 182 via a six-line location signal 184. Internally, linesI1 and I2 correspond to the two 64 kbps lines in (pins 4 and 5 of)ISDN-BRI line 48 a, lines I3 and I4 correspond to the two 64 kbps linesin (pins 4 and 5 of) ISDN-BRI line 48 b, and lines I5 and I6 correspondto the two 64 kbps lines in (pins 4 and 5 of) ISDN-BRI line 48 c. Thesesix lines I1-I6 are switched by switch bank 180 to lines A1-A6, B1-B6,C1-C6, D1-D6, E1-E6, or F1-F6, respectively, depending on which of thesix lines in the location signal 184 is active. The lines 105A, 105B,105C, 105D, 105E, and 105F preferably comprise eight-wire (four twistedpair) CAT-5 or CAT-6 cables. Since each line 105 includes more than two64 kbps ISDN U interfaces, i.e., includes six 64 kbps ISDN U interfaces(A1-A6, B1-B6, C1-C6, D1-D6, E1-E6, or F1-F6), lines 105A, 105B, 105C,105D, 105E, and 105F are referred to as “hybrid ISDN lines.” In a 384kbps application, in addition to carrying the six switched ISDN linesA1-A6, B1-B6, C1-C6, D1-D6, E1-E6, or F1-F6, each line (i.e., each CAT-5or CAT-6 cable) connecting the switch 104 to a location A-F also has anextra pair of conductors 186A, 186B, 186C, 186D, 186E, or 186F incircuit communication with the autodetect logic (not shown) of controlunit 182. Two conductors 188, 190 of pair of conductors 186A forLocation A are shown.

[0063] The control unit 182 is also in circuit communication with a bankof LED drivers 192, which drive LEDs 194A, 194B, 194C, 194D, 194E, and194F, corresponding to locations A-F, respectively. These LEDs 194indicate which one of the six locations, if any, currently has access tothe unswitched lines I1-I6. The LEDs 194 are preferably positioned nearthe line, or an indication of the line, to which each corresponds.

[0064] Referring now to FIG. 8a and FIG. 8b, an isometric view of theswitch 104 mounted in a 19″ rack having rails 200, 202 and a view of thefront panel 204 of switch 104 are shown. The switch 104 has an enclosure206 having brackets 208, 210 physically annexed thereto. Brackets 208,210 are secured to rack rails 204, 202, respectively, by suitablefasteners, e.g., screws 212, 214. Signal inputs 108 a-108 c and signaloutputs 106A-106F comprise RJ-45 receptacles in this particular switch104. LEDs 194A-194F are shown in proximity to signal outputs 106A-106F.Switched ISDN lines A1-A6, B1-B6, C1-C6, D1-D6, E1-E6, and F1-F6, andautodetect lines 186A-186F (FIG. 7), are electrically connected tosignal outputs (RJ-45 receptacles) 106A-106F, which have RJ-45connectors 220A-220F inserted therein to directly electrically connecttherewith, which connectors are electrically connected to lines105A-105F. Similarly, unswitched ISDN lines 48 a-48 c are connected toRJ-45 connectors 222 a-222 c, which are inserted to signal inputs (RJ-45receptacles) 108 a-108 c to place the unswitched ISDN lines I1-I6 intocircuit communication with the six 64 kbps lines in ISDN U interfaces 48a-48 c, respectively.

[0065] Referring now to FIG. 8c, the custom breakout cable 113 is shownschematically. As discussed above in connection with FIG. 4, because theembodiment of FIG. 4 uses hybrid ISDN lines, one cannot use standardcables to connect the videoconferencing equipment 102 at any of thelocations. Rather, one connects the network interface 24 of thevideoconferencing equipment 102 to one of the switched ISDN lines105A-105F via a custom breakout cable 113. The custom breakout cable 113divides a hybrid ISDN line portion 114 into three ISDN-BRI lines 116a-116 c and has three RJ-45 connectors 118 a-118 c at one end and has asingle RJ-45 connector 119 at the other end. Pins 7 and 8 in connector119 are shorted together to short autodetect lines 188 and 190 when theconnector 119 is inserted into receptacle 110 in wall plate 112 at anyof the locations A-F. In the alternative, these two pins can beconnected via a relatively low resistance connection. As shown in FIG.8c, lines S1 and S2 of connector 119 are broken out to lines S1 and S2of connector 118 a (pin 1 of connector 119 is routed to pin 4 ofconnector 118 a and pin 2 of connector 119 is routed to pin 5 ofconnector 118 a), lines S3 and S4 of connector 119 are broken out tolines S3 and S4 of connector 118 b (pin 3 of connector 119 is routed topin 4 of connector 118 a and pin 4 of connector 119 is routed to pin 5of connector 118 a), and lines S5 and S6 of connector 119 are broken outto lines S5 and S6 of connector 118 c (pin 5 of connector 119 is routedto pin 4 of connector 118 a and pin 6 of connector 119 is routed to pin5 of 25 connector 118 a).

[0066]FIGS. 9 and 10 show schematically portions of the switch bank 180and control unit 182 of the switch 104 in FIGS. 4, 7, and 8. Morespecifically, FIG. 9 shows the portion 230 of switch bank 180 thatcorresponds to location A and FIG. 10 shows the portion 232 of controlunit 182 that corresponds to location A. In switch bank 180 and controlunit 182, the circuitry 230 and 232 would be replicated for locationsB-F with appropriate interconnections for each location. In thisparticular implementation, switch bank 180 is implemented with quad CMOSanalog switches, and switch control unit 182 is implemented with quadCMOS analog switches and a few passive components. Thus, the circuitportions 230, 232 are implemented using quad CMOS analog switches and afew passive components. Switch bank portion 230 uses four CMOS analogswitches in quad CMOS analog switch U1 and two CMOS analog switches inquad CMOS analog switch U2. Control unit portion 232 uses two CMOSanalog switches in quad CMOS analog switch U3, three CMOS analogswitches in quad CMOS analog switch U4, and two resistors, R1 and R2.Virtually any CMOS analog switches could be used for thisimplementation; none of the parameters are particularly important. QuadCMOS analog switches were used because of their relative density andready availability. The switching time of the particular analog switchused is not critical because the switch 104 is used in a very lowfrequency environment. The on-resistance of the particular switches isalso not particularly critical. Switches with a maximum on-resistance of35 ohms are suitable. Signal inputs 108 a-108 c, which are in circuitcommunication with ISDN-BRI U-interface lines 48 a-48 c, and signaloutputs 106A-106F (106B-106F not shown), which are in circuitcommunication with hybrid ISDN lines 105A-105F (105B-105F not shown),comprise RJ-45 receptacles in this particular switch 104. The switch 104also requires a power supply (not shown) to provide the voltages neededfor the particular switch bank and control unit used. The power supplyfor the embodiment of FIGS. 9 and 10 supplies +8 VDC and −8 VDC, inaddition to ground.

[0067] The components for switch bank portion 230 and control unitportion 232 are placed in circuit communication as shown in FIGS. 9 and10. As shown in those figures, each of the six unswitched 64 kbps ISDNlines I1-I6 from the central office is in circuit communication with acommon pole of one of the SPDT switches in the quad CMOS analog switchesU1, U2. Each of the corresponding six switched 64 kbps ISDN lines A1-A6are in circuit communication with a corresponding normally open pole ofone of the SPDT switches in the quad CMOS analog switches U1, U2. Theallocation of the switches is not a critical aspect of the presentinvention. As should be apparent to those in the art, the individualanalog switches need not be allocated as shown in FIG. 9 and 10; asexamples, the two switches from U3 could have come from the remainingswitches in U2 and in the alternative, all the switches can come fromany combination or permutation of quad CMOS analog switches. Also,unswitched lines I1-I6 and switched lines B1-B6, C1-C6, D1-D6, E1-E6,and F1-F6 (all not shown in FIG. 9) are connected to portion 238 ofswitch bank 180 corresponding to locations B-F. Although not shown inFIGS. 9 and 10, all six select lines 184A-184F are also in circuitcommunication with portion 238 of switch bank 180 corresponding tolocations B-F.

[0068] As shown in FIGS. 9 and 10, the portion 232 of control unit 182corresponding to Location A is in circuit communication with autodetectlines 188 and 189 for Location A (collectively 186A), which correspondto pins 7 and 8 of receptacle 106A. Autodetect line 190 is connected to+V (8 VDC) and autodetect line 188 is in circuit communication with avoltage divider 234 via a plurality of normally closed analog switches.The voltage divider 234 comprises resistor R1 (3 kΩ) and resistor R2 (3kΩ) between line 188 and ground, as shown in FIG. 10. When lines 188 and190 are open, as when no audiovisual equipment is being used, location Aselect 184A is pulled to a logical low by resistor R2. When lines 188and 190 are closed, as when audiovisual equipment is being used,location A select 184A is pulled to a logical high by resistor divider234. In this particular implementation of the switch 104 of the presentinvention, the +V (V+) and −V (V−) lines for switches U1-U4 are at 8 VDCand −8 VDC, respectively. In general, autodetect line 188 is in circuitcommunication with a voltage divider 234 via a number of normally closedanalog switches equal to the number of locations being autodetected,minus one. In the particular example of FIGS. 9 and 10, there are sixlocations A-F. Thus, autodetect line 188 passes through five normallyclosed switches as shown in FIG. 10.

[0069] One location locks out the other locations as follows. On the onehand, if no other location is currently being detected, then all five ofthe location select lines 184B-184F are inactive, all five of thenormally closed switches in U3 and U4 remain closed, and the autodetectline 188 is in circuit communication with voltage divider 234. In thisstate, if autodetect lines 188 and 190 are shorted, or are connectedwith a relatively low resistance connection, then Location A select line184A is pulled up to about 4 VDC by voltage divider 234, which causesthe six normally open switches in U1 and U2 to close, which connectslines I1-I6 to A1-A6, respectively, i.e., the input signals are switchedto location A. The portions of switch bank 180 and control unit 182corresponding to Locations B-F function in the same way.

[0070] On the other hand, if any of the other locations is currentlybeing detected, then at least one of the five location select lines184B-184F is active, at least one of the corresponding normally closedswitches in U3 and U4 opens, and the autodetect line 188 is not incircuit communication with voltage divider 234. In this state, ifautodetect lines 188 and 190 are shorted, or are connected with arelatively low resistance connection, then nothing happens to Location Aselect line 184A; it remains pulled down to about 0 VDC (ground) byresistor R2. Thus, selecting another location effectively locks outlocation A, i.e., prevents closure of autodetect lines 188 and 190 fromaffecting Location A select line 184A. The portions of switch bank 180and control unit 182 corresponding to Locations B-F function in the sameway. Thus, if any location is active, the control unit locks out theother locations.

[0071] Additionally, the location selection lines 184A-184F are incircuit communication with typical LED drivers (one driver for each LED194A-194F, drivers not shown) used to drive (i.e., illuminate) the LED194 corresponding to the active location.

[0072] FIGS. 11-13 show different embodiments of the control unit 152shown in FIGS. 5 and 6. The embodiment of FIG. 11 is identical to theembodiment of FIG. 6, except the control unit 152 has both autodetectlogic 250 and a communication circuit 252. In both the embodiment ofFIG. 6 and the embodiment of FIG. 8, the communication link to eachlocation is via a communication link routed with, and preferably in thesame cable as, the switched communication lines 155-1, 155-2, . . .155-n. In the embodiment of FIG. 6, the signals on communication link162-1, 162-2, . . . 162-n are very simple, as discussed above. Theembodiment of FIG. 11 contemplates more sophisticated communication overcommunication link 254-1, 254-2, . . . 254-n between the control unit152 and the locations 1-n. Accordingly, the control unit 152 comprises acommunications circuit 252 to provide a communication protocol withcircuitry (not shown) at the locations 1-n. The circuitry at eachlocation contemplated by this embodiment is the same as the circuitry ateach location contemplated by the embodiment of FIG. 6 (e.g., circuitincluding a keypad, a circuit including a key card reader, and a circuitincluding a sensor), and located at the locations, except the circuitscontemplated by this embodiment require more elaborate communicationwith the control unit 152.

[0073] The more sophisticated communication of FIG. 11 might be requiredbecause the particular circuitry at a location might not be capable ofmaking a validation determination itself, but instead requires moreprocessing power. For example, the communications circuit 252 mightdevelop an RS-232 link or RS-422 link between the control unit 152 and akeypad or key card reader or pendant or other circuit at each location.Each time, for example, a key on the keypad is actuated, a valuecorresponding to the actuated key could be sent to the control unit viathe communications link 254-1, 254-2, or 254-n and the control unit 152itself would determine whether a series of keystrokes is valid. Thelocation that transmitted the valid set of keystrokes, having beendetermined by the autodetect logic 250, would then be communicated tothe switch bank 150 by the control unit 152 via the location signal 156.As with the embodiment of FIG. 6, the switched communication lines 155in the embodiment of FIG. 11 can, in the alternative, be used for bothautodetection and then communication, without the need for separateadditional lines being run from the switch 92 to the locations. In thisalternative embodiment, the switched communication lines 155 would beused first as a communication path 254 and then as switchedcommunication lines 155.

[0074] The embodiment of FIG. 12 is identical to the embodiment of FIG.11, except the sophisticated communication link 270 to each location isother than via a communication link routed with the switchedcommunication lines 155-1, 155-2, . . . 155-n. The embodiment of FIG. 12is an autodetect embodiment having a switch bank 150 and a control unitthat are essentially the same as in FIG. 11, except the communicationcircuitry 252 of FIG. 12 can take more forms. The communicationscircuitry 252 in FIG. 12 can be circuitry to generate one or anycombination of virtually any type of communications link: any protocolover one or more conductor(s), computer network(s), fiber optic link(s),optical signal(s), radio signal(s), electromagnetic signal(s), telephoneline(s), sonic link(s), power line(s) (using, e.g., an X-10 interface).The embodiment of FIG. 12 contemplates sophisticated communication overcommunication link 270-1, 270-2, . . . 270-n between the control unit152 and the locations 1-n, relative to the embodiment of FIG. 6. As withthe other embodiments, this embodiment includes circuitry (not shown) ateach location with which one requests use of the at least one unswitchedcommunication line 154. The circuitry at each location contemplated bythis embodiment includes at least the same circuitry at each locationcontemplated by the embodiment of FIG. 11 (e.g., circuit including akeypad, a circuit including a key card reader, and a circuit including asensor). Additionally, the use of virtually any communications interfacemakes use of other circuitry possible. For example, with a properinterface, the communication circuitry could implement a telephoneinterface (e.g., by making the control unit 152 appear as an telephoneextension or by interfacing directly with a firm's PBX) through whichpeople might dial a particular telephone extension to request access tothe unswitched communications lines. Then by using, for example, acaller-ID type function, or by direct access to the PBX, the autodetectlogic 250 would determine the identity of the location requestingaccess, which location would be transmitted to the switch bank 150 viathe location signal 156.

[0075] The embodiment of FIG. 13 is similar to the embodiment of FIG.12, except the sophisticated communication link 280 is directed to atleast one communications device 282 located at locations other than atthe locations 1-n. The embodiment of FIG. 13 differs from the otherembodiments in that it is not an autodetect embodiment; a user using thecommunications device 282 to directly selects or indicates whichparticular location to which the at least one unswitched communicationsline 154 is to be switched. The communications circuitry 252 in FIG. 13can be circuitry to generate one or any combination of virtually anytype of communications link: any protocol over one or more conductor(s),computer network(s), fiber optic link(s), optical signal(s), radiosignal(s), electromagnetic signal(s), telephone line(s), sonic link(s),power line(s) (using, e.g., an X-10 interface). The communicationsdevices 282 contemplated by this embodiment includes at least thefollowing: (a) a telephone (e.g., by making the control unit 152 appearas an telephone extension or by interfacing directly with a firm's PBX)through which people might dial a series of numbers to switch access tothe at least one unswitched communications line 154, (b) a desktopcomputer (e.g., by implementing an RS-232 or other standard computerinterface or by interfacing the control unit 152 to a computer networkwith the communications circuit 252) with which one would select alocation, (c) a palm top computer (e.g., by implementing a wirelessinterface), (d) a web browser (e.g., by implementing a URL for thecontrol circuit 152) with which one would select a location, (e) akeypad located, e.g., on the enclosure for the switch, or at thelocation where the switch is located, or located at some other location.The numerous communications links contemplated by the embodiments ofFIG. 12 and FIG. 13 can be connected to the switch 92 by any suitableconnector placed in circuit communication with the control unit by anycircuit communication means. Using a computer interfaced to the controlunit via the communication circuit, such selection of a location can bemade with any number of commonly known computer interfaces, such as acommand line interface (e.g., a “switchto destination” command, e.g.,switchto cr13ne (conference room 13 Northeast)) or with a graphical userinterface (e.g., having an icon for each unswitched communication lineand an icon for each location and clicking on and dragging unswitchedcommunication line(s) to location(s)). Using a telephone interfaced tothe control unit via the communication circuit, such selection of alocation can be made with any number of commonly used telephoneinterfaces, such as an audible menu-driven interface (e.g., “press 1 toselect a location for the ISDN lines to be switched to,” “press 2 toknow the location currently accessing the ISDN lines,” “press 3 to knowthe status of the automatic ISDN switch,” etc.) or having particularnumber codes cause each action (e.g., pressing 1-1 causes the switch toroute the lines to a first location, pressing 1-2 causes the switch toroute the lines to a second location, pressing 9-9 causes the switch toroute the lines to none of the locations, etc.). Such commands viatelephone, computer, etc. can be expected to be carried out virtuallyimmediately or, in the alternative, at some other date and/or time byaddition of other parameter(s) to the command, which would allowscheduling of resources in advance (e.g., a “switchto destination ondate at time” command).

[0076] Using the embodiment of FIG. 13 also allows added functionalityto the control unit, such as allowing a user to allocate a plurality ofunswitched communications lines to more than one location with anenhanced (not one-of-n) switch bank. This type of user-selectedbandwidth on demand has obvious advantages, such as flexibility. Forexample, in a system having six ISDN-BRI U interface lines from thecentral office, using any of the communications devices listed herein(or others) one might command the control unit to cause the switch bankto allocate three ISDN-BRI lines to location A for a 384 kbpsvideoconferencing session, one ISDN-BRI lines to location C for aweb-browsing software demonstration, and leave the other two linesunallocated. Using a computer interfaced to the control unit via thecommunication circuit, such allocation can be made with a command lineinterface (e.g., a “switch source to destination” command, e.g., switchlines 1-3 to cr13ne) or with a graphical user interface (e.g., having anicon for each unswitched communication line and an icon for eachlocation and clicking on and dragging unswitched communication line(s)to location(s)). Using a telephone interfaced to the control unit viathe communication circuit, such allocation of line(s) to locations canbe made with any number of commonly used telephone interfaces, such asan audible menu-driven interface (e.g., “press 1 to allocatecommunication lines,” “select a communication line to allocate,” “selecta location for that line to be allocated to,” “press 8 to know thelocation currently accessing the ISDN lines,” “press 8 to know thestatus of the automatic ISDN switch,” etc.) or having particular numbercodes cause each action (e.g., pressing 1-1-1 causes the switch to routethe first communication line to the first location, pressing 1-1-2causes the switch to route the first communication line to the secondlocation, pressing 1-2-1 causes the switch to route the secondcommunication line to the first location, pressing 1-2-2 causes theswitch to route the second communication line to the second location,pressing 9-9 causes the switch to route the lines to none of thelocations, etc.). Such commands via telephone, computer, etc. can beexpected to be carried out virtually immediately or, in the alternative,at some other date and/or time by addition of other parameter(s) to thecommand, which would allow scheduling of resources in advance (e.g., a“switch source to destination on date at time” command).

[0077] The control units herein will differ from embodiment toembodiment, in terms of circuitry and processing power required. Forexample, in the embodiment of FIG. 7, the determination of the desiredlocation from the lines 186A-186F is very straightforward-virtually nocircuitry at all is needed to determine the location and communicatethat to the switch bank 180. However, in the case of other embodiments,e.g., the telephone interface and computer interface embodiments, thecontrol unit will need additional circuitry and processing power. Asknown to those in the art, such additional processing power can beprovided by any number of processors in circuit communication with theautodetect logic and/or the communications circuitry, e.g., programmablelogic controllers (PLCs), PICs, microcontrollers, microprocessors withassociated logic and memory, etc. In all of these examples herein, andfor every embodiment and alternative, the control unit merely needs tobe provided with suitable interface hardware circuitry and programmed torespond to each command. Telephone embodiments will preferably need tobe able to respond to buttons being pressed or voice commands. Thismight be implemented with the control unit providing DTMF or otherbutton decoding or with the PBX system doing most of the work andpassing commands to the control unit via the communications link. Thecomputer embodiments might be implemented with the computercommunications device acting as a simple terminal passing commands backand forth to and from the control unit acting as a terminal host, orwith an elaborate computer program executing on the computercommunications device and the control unit acting as merely an extensionof that computer and its program, or anything in between those twoextremes. Given the present disclosure, implementation of each controlunit is believed to be within the capabilities of those skilled in theart.

[0078] The control unit can also perform the function of determining (orallowing a user to communicate) whether permission has been granted forat least one communication line to be used at a particular location at aparticular time. For example, before allowing input from any of thecommunications devices, e.g., key pad, computer, telephone, palm-top,pendant, etc., the control unit can be configured and programmed torequire that a password be input through that device or another device.Also, the permission function can be added to any of the autodetectembodiments. For example, recall that in the embodiment of FIGS. 7-9 thecontrol unit automatically generates the location signal responsive toinsertion of an ISDN connector into an ISDN receptacle. In thealternative, one might add to the embodiment of FIGS. 7-9 acommunications circuit of FIG. 12 providing a communications link toeach location via telephones and associated telephone wiring. Althoughthe control unit would generate the location signal in response to theconnector being inserted into the receptacle, it would not do soautomatically; rather the control unit would wait for some form ofpermission indicator before generating the location signal, e.g., thecontrol unit would wait for a user to pick up one of the handsets, dialan extension, and actuate a specific series of buttons on the telephonekeypad before generating the location signal. Thus, the control unit canbe configured to determine whether permission has been granted for theproposed use of the communication signals. Additionally, as is apparentfrom this embodiment, the control unit (in this and all embodiments) canautomatically generate the location signal, thereby causing the switchbank to switch the lines, or in the alternative, the control unit canrequire that some other action be performed before generating thelocation signal. In the former automatic configuration, the locationsignal can comprise merely an indication of the desired location. In thelatter configuration, the location signal would need an additional line(e.g., a strobe signal or a data valid signal) to command the switchbank to switch the communications lines.

[0079] The control unit can also perform the function of providingsystem status, e.g., whether ISDN lines are already in use, where theISDN lines are in use, who accessed the system to use ISDN lines,whether anyone has scheduled use of lines at a particular date and time,etc. Such status indications can be transmitted by the control unit inany number of ways, e.g., having a digitized or synthesized voicepresent status information using a telephone line; leaving voice mailcontaining status information to someone using a digitized orsynthesized voice either using the PBX directly or via telephone lines;sending an e-mail message containing status information to someone via acomputer network or via an intranet or via the Internet; sending statusinformation via the communications devices discussed herein or via adisplay associated with any of the communications devices discussedherein, etc.

[0080] The “communications line(s)” referred to herein can refer to ISDNU interface lines, other ISDN lines, fiber optic lines, Ethernet lines,asynchronous transfer mode (ATM) lines, digital subscriber line (DSL)lines virtually any type of communications link that should beterminated at a single location would benefit from the presentinvention. The term “user” is used broadly herein as meaning a user ofvideoconferencing equipment as well as a user of the control unit and/orswitch bank of the present invention.

[0081] Using the automatic switch of the present invention is verystraightforward. First the switch is connected to unswitchedcommunications lines, switched communications lines, circuitry,communications devices, and power source in accordance with the abovediscussion. Then the videoconferencing equipment and any communicationsdevices are connected to appropriate power and signal lines as should beapparent from the particular embodiment and implementation being used.

[0082] Use of the various autodetect embodiments should be apparentafter the foregoing discussion. For example, using the breakout cable ofFIG. 8c, one merely inserts connector 119 into the ISDN receptacle 110in the desired location and the three ISDN-BRI lines 48 a-48 c areautomatically switched to lines 116 a-116 c. One inserts the three otherconnectors 118 a-118 c into the network interface 24 to complete thebreakout of the hybrid lines. As another example, using the key cardautodetect embodiments, one merely swipes the key card through the cardreader located at the desired location and the three ISDN-BRI lines 48a-48 c are automatically switched to that location. As yet anotherexample, using the keypad autodetect embodiments, one merely types inthe correct code using the keypad located at the desired location andthe three ISDN-BRI lines 48 a-48 c are automatically switched to thatlocation. As a final example, using the telephone buttonbased autodetectembodiments, one merely picks up the handset and dials a particularextension using the telephone located at the desired location and thethree ISDN-BRI lines 48 a-48 c are automatically switched to thatlocation. In general, one merely performs the act(s) at the locationthat causes the control unit to generate the location signal, which inturn causes the switch bank to switch the communications lines asdesired.

[0083] Use of the communications embodiments should also be apparentafter the foregoing discussion. For example, using computer or palm-topembodiments, one merely types one or more commands or actuates one ormore icons on the computer interfaced to the control unit via thecommunications circuit to switch or allocate communications lines toselected locations. As another example, using the telephone button-basedembodiments, one merely picks up the handset and dials a particularextension using the telephone interfaced to the control unit via thecommunications circuit and presses buttons (e.g., either codesrepresenting commands or in response to audible prompts) to switch orallocate communications lines to selected locations. In general, onemerely communicates to the control unit with one or more communicationdevices the desired action, thereby causing the control unit to generatethe location signal, which in turn causes the switch bank to switch thecommunications lines as desired.

[0084] While the present invention has been illustrated by thedescription of embodiments thereof, and while the embodiments have beendescribed in considerable detail, it is not the intention of theapplicant to restrict or in any way limit the scope of the appendedclaims to such detail. Additional advantages and modifications willreadily appear to those skilled in the art. For example, any combinationand permutation of the one or more communications links and devices fromeach embodiment can be combined, for example autodetection at eachlocation via a telephone extension, a keypad on the switch enclosure,and computer access via an RS-232 link. As another example, there can bemore than one communication device at each location or different devicesat the various locations, for example, a keypad in location A and keycard reader in location C. Therefore, the invention in its broaderaspects is not limited to the specific details, representative apparatusand method, and illustrative examples shown and described. Accordingly,departures may be made from such details without departing from thespirit or scope of the applicant's general inventive concept.

We claim:
 1. An automatic ISDN switch for connection to at least oneISDN-BRI line and a plurality of different videoconferencing locationsfor automatically switching the at least one ISDN-BRI line to onevideoconferencing location of the plurality of differentvideoconferencing locations, comprising: (a) a control unit for beingplaced in circuit communication with each of the plurality of differentvideoconferencing locations, said control unit generating a locationsignal corresponding to a particular one videoconferencing location ofthe plurality of videoconferencing locations; and (b) a switch bank incircuit communication with said control unit for receiving the locationsignal, for being placed in circuit communication with the plurality ofdifferent videoconferencing locations, and further for being placed incircuit communication with the at least one ISDN-BRI line, said switchbank automatically switching the at least one ISDN-BRI line to theparticular one videoconferencing location of the plurality ofvideoconferencing locations corresponding to the location signalgenerated by the control unit.
 2. The automatic ISDN switch of claim 1 ,(a) wherein each of the plurality of different videoconferencinglocations comprises an ISDN receptacle, each of said plurality of ISDNreceptacles for being placed in circuit communication with said controlunit; and (b) wherein said control unit generates the location signalcorresponding to the particular one videoconferencing locationresponsive to an ISDN connector being inserted into the ISDN receptaclein the particular one videoconferencing location.
 3. The automatic ISDNswitch of claim 2 , wherein said control unit automatically generatesthe location signal corresponding to the particular onevideoconferencing location responsive to an ISDN connector beinginserted into the ISDN receptacle in the particular onevideoconferencing location.
 4. The automatic ISDN switch of claim 1 ,(a) wherein each of the plurality of different videoconferencinglocations comprises an ISDN receptacle, each of said plurality of ISDNreceptacles for being placed in circuit communication with said controlunit via at least first and second conductors; and (b) wherein theinsertion of an ISDN connector into the ISDN receptacle in theparticular one videoconferencing location significantly reduces theimpedance between the first and second conductors for the particular onevideoconferencing location; and (c) wherein said control unit generatesthe location signal corresponding to the particular onevideoconferencing location responsive to detecting the change in theimpedance between the first and second conductors for the particular onevideoconferencing location.
 5. The automatic ISDN switch of claim 4 ,wherein said control unit automatically generates the location signalcorresponding to the particular one videoconferencing locationresponsive to detecting the change in the impedance between the firstand second conductors for the particular one videoconferencing location.6. The automatic ISDN switch of claim 1 , (a) wherein each of theplurality of different videoconferencing locations comprises an ISDNreceptacle, each of said plurality of ISDN receptacles for being placedin circuit communication with said control unit via at least first andsecond conductors; and (b) wherein the insertion of an ISDN connectorinto the ISDN receptacle in the particular one videoconferencinglocation causes a change in the electrical relationship between thefirst and second conductors for the particular one videoconferencinglocation; and (c) wherein said control unit generates the locationsignal corresponding to the particular one videoconferencing locationresponsive to detecting the change in the electrical relationshipbetween the first and second conductors for the particular onevideoconferencing location.
 7. The automatic ISDN switch of claim 6 ,wherein said control unit automatically generates the location signalcorresponding to the particular one videoconferencing locationresponsive to detecting the change in the electrical relationshipbetween the first and second conductors for the particular onevideoconferencing location.
 8. The automatic ISDN switch of claim 1 ,wherein said control unit generates the location signal corresponding tothe particular one videoconferencing location responsive to a userperforming at least one action in the particular one videoconferencinglocation.
 9. The automatic ISDN switch of claim 1 , wherein said controlunit automatically generates the location signal corresponding to theparticular one videoconferencing location responsive to a userperforming at least one action in the particular one videoconferencinglocation.
 10. The automatic ISDN switch of claim 1 , wherein saidcontrol unit generates the location signal corresponding to theparticular one videoconferencing location responsive to a user turningon at least a portion of videoconferencing equipment in the particularone videoconferencing location.
 11. The automatic ISDN switch of claim 1, wherein said control unit automatically generates the location signalcorresponding to the particular one videoconferencing locationresponsive to a user turning on at least a portion of videoconferencingequipment in the particular one videoconferencing location.
 12. Theautomatic ISDN switch of claim 1 , wherein said control unit is locatedin an installed location and said control unit generates the locationsignal corresponding to the particular one videoconferencing locationresponsive to a user performing at least one action in a locationdifferent from the installed location where the control unit is located.13. The automatic ISDN switch of claim 1 , wherein said control unit islocated in an installed location and said control unit automaticallygenerates the location signal corresponding to the particular onevideoconferencing location responsive to a user performing at least oneaction in a location different from the installed location where thecontrol unit is located.
 14. An automatic ISDN switch for automaticallyswitching at least one signal input, said signal input corresponding toat least one ISDN-BRI line, to at least one particular signal output ofa plurality of signal outputs, each of said signal outputs correspondingto one videoconferencing location of a plurality of differentvideoconferencing locations, comprising: (a) a control unit, saidcontrol unit generating a location signal corresponding to a particularone videoconferencing location of the plurality of videoconferencinglocations; and (b) a switch bank in circuit communication with the atleast one signal input and with the plurality of signal outputs, andfurther in circuit communication with said control unit for receivingthe location signal, said switch bank automatically switching the atleast one signal input to the at least one particular signal output ofthe plurality of signal outputs corresponding to the location signalgenerated by the control unit.
 15. The automatic ISDN switch of claim 14, wherein said control unit generates the location signal correspondingto the particular one videoconferencing location responsive to an ISDNconnector being inserted into an ISDN receptacle in the particular onevideoconferencing location.
 16. The automatic ISDN switch of claim 18 ,wherein said control unit automatically generates the location signalcorresponding to the particular one videoconferencing locationresponsive to an ISDN connector being inserted into the ISDN receptaclein the particular one videoconferencing location.
 17. The automatic ISDNswitch of claim 14 , (a) wherein each of the plurality of differentvideoconferencing locations comprises an ISDN receptacle, each of saidplurality of ISDN receptacles for being placed in circuit communicationwith said control unit via at least first and second conductors; and (b)wherein the insertion of an ISDN connector into the ISDN receptacle inthe particular one videoconferencing location significantly reduces theimpedance between the first and second conductors for the particular onevideoconferencing location; and (c) wherein said control unit generatesthe location signal corresponding to the particular onevideoconferencing location responsive to detecting the change in theimpedance between the first and second conductors for the particular onevideoconferencing location.
 18. The automatic ISDN switch of claim 20 ,wherein said control unit automatically generates the location signalcorresponding to the particular one videoconferencing locationresponsive to detecting the change in the impedance between the firstand second conductors for the particular one videoconferencing location.19. The automatic ISDN switch of claim 14 , (a) wherein each of theplurality of different videoconferencing locations comprises an ISDNreceptacle, each of said plurality of ISDN receptacles for being placedin circuit communication with said control unit via at least first andsecond conductors; and (b) wherein the insertion of an ISDN connectorinto the ISDN receptacle in the particular one videoconferencinglocation causes a change in the electrical relationship between thefirst and second conductors for the particular one videoconferencinglocation; and (c) wherein said control unit generates the locationsignal corresponding to the particular one videoconferencing locationresponsive to detecting the change in the electrical relationshipbetween the first and second conductors for the particular onevideoconferencing location.
 20. The automatic ISDN switch of claim 22 ,wherein said control unit automatically generates the location signalcorresponding to the particular one videoconferencing locationresponsive to detecting the change in the electrical relationshipbetween the first and second conductors for the particular onevideoconferencing location.
 21. The automatic ISDN switch of claim 14 ,wherein said control unit generates the location signal corresponding tothe particular one videoconferencing location responsive to a userperforming at least one action in the particular one videoconferencinglocation.
 22. The automatic ISDN switch of claim 14 , wherein saidcontrol unit automatically generates the location signal correspondingto the particular one videoconferencing location responsive to a userperforming at least one action in the particular one videoconferencinglocation.
 23. The automatic ISDN switch of claim 14 , wherein saidcontrol unit generates the location signal corresponding to theparticular one videoconferencing location responsive to a user turningon at least a portion of videoconferencing equipment in the particularone videoconferencing location.
 24. The automatic ISDN switch of claim14 , wherein said control unit automatically generates the locationsignal corresponding to the particular one videoconferencing locationresponsive to a user turning on at least a portion of videoconferencingequipment in the particular one videoconferencing location.
 25. Theautomatic ISDN switch of claim 14 , wherein said control unit is locatedin an installed location and said control unit generates the locationsignal corresponding to the particular one videoconferencing locationresponsive to a user performing at least one action in a locationdifferent from the installed location where the control unit is located.26. The automatic ISDN switch of claim 14 , wherein said control unit islocated in an installed location and said control unit automaticallygenerates the location signal corresponding to the particular onevideoconferencing location responsive to a user performing at least oneaction in a location different from the installed location where thecontrol unit is located.
 27. The automatic ISDN switch of claim 14 ,wherein said signal outputs are hybrid ISDN lines.
 28. The automaticISDN switch of claim 15 , wherein said signal outputs are hybrid ISDNlines.
 29. The automatic ISDN switch of claim 22 , wherein said signaloutputs are hybrid ISDN lines.
 30. An automatic ISDN switch forautomatically switching at least one signal input, said signal inputcorresponding to at least one hybrid ISDN line, to at least oneparticular signal output of a plurality of signal outputs, each of saidsignal outputs corresponding to one videoconferencing location of aplurality of different videoconferencing locations, comprising: (a) acontrol unit, said control unit generating a location signalcorresponding to a particular one videoconferencing location of theplurality of videoconferencing locations; and (b) a switch bank incircuit communication with the at least one signal input and with theplurality of signal outputs, and further in circuit communication withsaid control unit for receiving the location signal, said switch bankautomatically switching the at least one signal input to the at leastone particular signal output of the plurality of signal outputscorresponding to the location signal generated by the control unit. 31.The automatic ISDN switch of claim 30 , wherein said signal outputs arehybrid ISDN lines.